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At least 505 records · Page 28

The Sun and the Heliosphere as an Integrated System

This book, for the first time, ties together physical processes across the full scale of the heliosphere. It is about the natural connections that exist between various parts of the system. Therefore, it is mainly cast in terms of those mechanisms and phenomena rather than individual missions in space. However, to give credit, this has only been possible because of the existence of a fleet of deep space missions such as Ulysses, SOHO, and the Voyagers. It is only with them working in concert that a real understanding of the physics can be, and has been achieved. There are fourteen chapters in the book, written by top scientists from around the world. The level of presentation is very high but the authors were given enough space to present understandable introductions, physical discussions, and extensive bibliographies. The book can be of use to average scientists and academicians as well as to specialists.

Poletto, Giannina↗

Bi-Level Integrated System Synthesis (BLISS)

BLISS is a method for optimization of engineering systems by decomposition. It separates the system level optimization, having a relatively small number of design variables, from the potentially numerous sub-system optimizations that may each have a large number of local design variables. The subsystem optimizations are autonomous and may be conducted concurrently. Subsystem and system optimizations alternate, linked by sensitivity data, producing a design improvement in each iteration. Starting from a best guess initial design, the method improves that design in iterative cycles, each cycle comprised of two steps. In step one, the system level variables are frozen and the improvement is achieved by separate, concurrent, and autonomous optimizations in the local variable subdomains. In step two, further improvement is sought in the space of the system level variables. Optimum sensitivity data link the second step to the first. The method prototype was implemented using MATLAB and iSIGHT programming software and tested on a simplified, conceptual level supersonic business jet design, and a detailed design of an electronic device.

Sobieszczanski-Sobieski, Jaroslaw↗

Optimal Design of Integrated Systems Health Management (ISHM) Systems for improving safety in NASA's Exploration Vehicles: A Two-Level Multidisciplinary Design Approach

In this paper, a two-level multidisciplinary design approach is described to optimize the effectiveness of ISHM s. At the top level, the overall safety of the mission consists of system-level variables, parameters, objectives, and constraints that are shared throughout the system and by all subsystems. Each subsystem level will then comprise of these shared values in addition to subsystem-specific variables, parameters, objectives and constraints. A hierarchical structure will be established to pass up or down shared values between the two levels with system-level and subsystem-level optimization routines.

Tumer, Irem↗

Plasma Measurements in an Integrated-System FARAD Thruster

Pulsed inductive plasma accelerators are spacecraft propulsion devices in which energy is stored in a capacitor and then discharged through an inductive coil. The device is electrodeless, inducing a current sheet in a plasma located near the face of the coil. The propellant is accelerated and expelled at a high exhaust velocity (order of 10 km/s) through the interaction of the plasma current and the induced magnetic field. The Faraday Accelerator with RF-Assisted Discharge (FARAD) thruster[1,2] is a type of pulsed inductive plasma accelerator in which the plasma is preionized by a mechanism separate from that used to form the current sheet and accelerate the gas. Employing a separate preionization mechanism allows for the formation of an inductive current sheet at much lower discharge energies and voltages than those used in previous pulsed inductive accelerators like the Pulsed Inductive Thruster (PIT). A benchtop FARAD thruster was designed following guidelines and similarity performance parameters presented in Refs. [3,4]. This design is described in detail in Ref. [5]. In this paper, we present the temporally and spatially resolved measurements of the preionized plasma and inductively-accelerated current sheet in the FARAD thruster operating with a Vector Inversion Generator (VIG) to preionize the gas and a Bernardes and Merryman circuit topology to provide inductive acceleration. The acceleration stage operates on the order of 100 J/pulse. Fast-framing photography will be used to produce a time-resolved, global view of the evolving current sheet. Local diagnostics used include a fast ionization gauge capable of mapping the gas distribution prior to plasma initiation; direct measurement of the induced magnetic field using B-dot probes, induced azimuthal current measurement using a mini-Rogowski coil, and direct probing of the number density and electron temperature using triple probes.

Polzin, K. A.↗

Human Systems Integration: Unmanned Aircraft Control Station Certification Plan Guidance

This document provides guidance to the FAA on important human factors considerations that can be used to support the certification of a UAS Aircraft Control Station (ACS). This document provides a synopsis of the human factors analysis, design and test activities to be performed to provide a basis for FAA certification. The data from these analyses, design activities, and tests, along with data from certification/qualification tests of other key components should be used to establish the ACS certification basis. It is expected that this information will be useful to manufacturers in developing the ACS Certification Plan,, and in supporting the design of their ACS.

Source record↗

Implementation of Integrated System Fault Management Capability

Fault Management to support rocket engine test mission with highly reliable and accurate measurements; while improving availability and lifecycle costs. CORE ELEMENTS: Architecture, taxonomy, and ontology (ATO) for DIaK management. Intelligent Sensor Processes; Intelligent Element Processes; Intelligent Controllers; Intelligent Subsystem Processes; Intelligent System Processes; Intelligent Component Processes.

Figueroa, Fernando↗

Vulnerabilities, Influences and Interaction Paths: Failure Data for Integrated System Risk Analysis

We describe graph-based analysis methods for identifying and analyzing cross-subsystem interaction risks from subsystem connectivity information. By discovering external and remote influences that would be otherwise unexpected, these methods can support better communication among subsystem designers at points of potential conflict and to support design of more dependable and diagnosable systems. These methods identify hazard causes that can impact vulnerable functions or entities if propagated across interaction paths from the hazard source to the vulnerable target. The analysis can also assess combined impacts of And-Or trees of disabling influences. The analysis can use ratings of hazards and vulnerabilities to calculate cumulative measures of the severity and importance. Identification of cross-subsystem hazard-vulnerability pairs and propagation paths across subsystems will increase coverage of hazard and risk analysis and can indicate risk control and protection strategies.

Malin, Jane T.↗

Intelligent Sensors for Integrated Systems Health Management (ISHM)

IEEE 1451 Smart Sensors contribute to a number of ISHM goals including cost reduction achieved through: a) Improved configuration management (TEDS); and b) Plug-and-play re-configuration. Intelligent Sensors are adaptation of Smart Sensors to include ISHM algorithms; this offers further benefits: a) Sensor validation. b) Confidence assessment of measurement, and c) Distributed ISHM processing. Space-qualified intelligent sensors are possible a) Size, mass, power constraints. b) Bus structure/protocol.

Schmalzel, John L.↗

N plus 2 Supersonic Concept Development and Systems Integration

Supersonic airplanes for two generations into the future (N+2, 2020-2025 EIS) were designed: the 100 passenger 765-072B, and the 30 passenger 765-076E. Both achieve a trans-Atlantic range of about 4000nm. The larger 765-072B meets fuel burn and emissions goals forecast for the 2025 time-frame, and the smaller 765-076E improves the boom and confidence in utilization that accompanies lower seat count. The boom level of both airplanes was reduced until balanced with performance. The final configuration product is two "realistic", non-proprietary future airplane designs, described in sufficient detail for subsequent multi-disciplinary design and optimization, with emphasis on the smaller 765-076E because of its lower boom characteristics. In addition IGES CAD files of the OML lofts of the two example configurations, a non-proprietary parametric engine model, and a first-cycle Finite Element Model are also provided for use in future multi-disciplinary analysis, optimization, and technology evaluation studies.

Wedge, Harry R.↗

Future Integrated Systems Concept for Preventing Aircraft Loss-of-Control Accidents

Loss of control remains one of the largest contributors to aircraft fatal accidents worldwide. Aircraft loss-of-control accidents are highly complex in that they can result from numerous causal and contributing factors acting alone or (more often) in combination. Hence, there is no single intervention strategy to prevent these accidents. This paper presents future system concepts and research directions for preventing aircraft loss-of-control accidents.

Belcastro, Christine M.↗

Integrated System Health Management (ISHM) Implementation in Rocket Engine Testing

A pilot operational ISHM capability has been implemented for the E-2 Rocket Engine Test Stand (RETS) and a Chemical Steam Generator (CSG) test article at NASA Stennis Space Center. The implementation currently includes an ISHM computer and a large display in the control room. The paper will address the overall approach, tools, and requirements. It will also address the infrastructure and architecture. Specific anomaly detection algorithms will be discussed regarding leak detection and diagnostics, valve validation, and sensor validation. It will also describe development and use of a Health Assessment Database System (HADS) as a repository for measurements, health, configuration, and knowledge related to a system with ISHM capability. It will conclude with a discussion of user interfaces, and a description of the operation of the ISHM system prior, during, and after testing.

Figueroa, Fernando↗

Integrated Systems Health Management (ISHM) Toolkit

A framework of software components has been implemented to facilitate the development of ISHM systems according to a methodology based on Reliability Centered Maintenance (RCM). This framework is collectively referred to as the Toolkit and was developed using General Atomics' Health MAP (TM) technology. The toolkit is intended to provide assistance to software developers of mission-critical system health monitoring applications in the specification, implementation, configuration, and deployment of such applications. In addition to software tools designed to facilitate these objectives, the toolkit also provides direction to software developers in accordance with an ISHM specification and development methodology. The development tools are based on an RCM approach for the development of ISHM systems. This approach focuses on defining, detecting, and predicting the likelihood of system functional failures and their undesirable consequences.

Venkatesh, Meera↗

Project Orion, Environmental Control and Life Support System Integrated Studies

Orion is the next vehicle for human space travel. Humans will be sustained in space by the Orion subystem, environmental control and life support (ECLS). The ECLS concept at the subsystem level is outlined by function and technology. In the past two years, the interface definition with other subsystems has increased through different integrated studies. The paper presents the key requirements and discusses three recent studies (e.g., unpressurized cargo) along with the respective impacts on the ECLS design moving forward.

Russell, James F.↗